Objective: To evaluate any possible association between indicators of social inequalities and the geographical distribution of HIV-1 mother-to-child transmission (MTCT) cases in Madrid.
Methods: We carried out an observational survey of 224 HIV-1 vertically infected children born in 1980–2006 living in Madrid. We elaborated maps representing the prevalence of HIV-1 MTCT cases. We assessed the association between indicators of social inequalities and the spatial distribution of MTCT cases. Poisson univariate and multivariate analysis of risk factors for MTCT were performed.
Results: We identified core areas of transmission mainly in southern Madrid until 2006. The prevalence of MTCT cases was significantly correlated to the percentage of immigrants, illiterates, unemployed women and the income in 1996 and 2000/2001. The risk of MTCT increased in the periods up to 1996 compared with the calendar period 1980–1989, whereas the risk decreased in 1999–2006 [relative risk, 0.08; 95% confidence interval (CI), 0.03–0.18; P < 0.001]. The risk was especially high in the districts of Usera (absolute relative risk, 11.4; 95% CI, 2.6–49.5; P = 0.001), Puente de Vallecas (absolute relative risk, 14.0; 95% CI, 3.4–57.9; P < 0.001) and San Blas (absolute relative risk, 12.5; 95% CI, 2.9–53.6; P = 0.001). The percentage of illiterates was the indicator that explained the risk of MTCT (absolute relative risk, 1.07; 95% CI, 1.05–1.10; P = 0.001).
Conclusion: We observed a geographic heterogeneity of the HIV-1 vertical transmission with the highest prevalence in disadvantaged districts. What is described in the present review is the HIV-1 vertical transmission within a social context; this approach could be relevant in analysing the pattern of HIV-1 transmission in other Western cities or highlighting the distribution of other infectious diseases.
aLaboratorio de Inmuno-Biología Molecular, Hospital General Universitario ‘Gregorio Marañón’, Madrid, Spain
bIstituto Pasteur, Fondazione Cenci-Bolognetti, Italy
cUniversità degli Studi di Roma ‘La Sapienza’, Rome, Italy
dUnitat d'Epidemiologia i Estadistica, Escola Valenciana d'Estudis per a la Salut, Valencia, Spain
eServicio de Infecciosas Pediátricas, Hospital Universitario Doce de Octubre, Spain
fSección Inmuno-Pediatría, Hospital Materno Infantil Gregorio Marañón, Spain
gServicio de Pediatría, Hospital Universitario de Getafe, Spain
hServicio Infecciosas Infantil, Hospital Universitario La Paz, Spain
iServicio de Pediatría, Hospital Universitario Carlos III, Madrid, Spain.
Received 18 April, 2008
Revised 16 June, 2008
Accepted 2 July, 2008
Correspondence to Dra. Ma Ángeles Muñoz-Fernández, Laboratorio Inmuno-Biología Molecular, Hospital General Universitario ‘Gregorio Marañón’, C/Doctor Esquerdo 46, 28007 Madrid, Spain. Tel: +34 91 586 8565; fax: +34 91 586 8018; e-mail: firstname.lastname@example.org